I use pylint, http://pypi.python.org/pypi/pylint, it is an excellent tool to try to keep your code clean and readable for you and other developers accessing your code.
I does not cover all topics you said, though, but it is very useful.
You can have reports like this one:
carlos@debian:~/src/fcl/cltools$ pylint numbertoletters.py
No config file found, using default configuration
************* Module numbertoletters
C: 1: Missing docstring
C: 56:es_numero: Missing docstring
C: 56:es_numero: Invalid name "s" (should match [a-z_][a-z0-9_]{2,30}$)
C: 56:es_numero: Invalid name "s" (should match [a-z_][a-z0-9_]{2,30}$)
C: 69:convertnumbertoletters: Empty docstring
C: 90:convertnumbertoletters: Operator not preceded by a space
numero='%(numero)09d' % {'numero' : int(parte_entera)}
^
C: 92:convertnumbertoletters: Comma not followed by a space
for i in [0,3,6]:
^^
W: 69:convertnumbertoletters: Unused argument 'languaje'
C:108:unidades: Empty docstring
C:108:unidades: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:108:unidades: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:112:unidades: Invalid name "u" (should match [a-z_][a-z0-9_]{2,30}$)
C:118:teens: Empty docstring
C:118:teens: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:118:teens: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:122:teens: Invalid name "t" (should match [a-z_][a-z0-9_]{2,30}$)
C:127:tens: Empty docstring
C:127:tens: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:127:tens: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
C:131:tens: Invalid name "t" (should match [a-z_][a-z0-9_]{2,30}$)
C:137:tercia: Empty docstring
C:141:tercia: Operator not preceded by a space
numero='%(numero)03d' % {'numero' : int(num)}
^
C:143:tercia: Invalid name "a" (should match [a-z_][a-z0-9_]{2,30}$)
C:144:tercia: Invalid name "b" (should match [a-z_][a-z0-9_]{2,30}$)
C:145:tercia: Invalid name "c" (should match [a-z_][a-z0-9_]{2,30}$)
C:163:tercia: Operator not followed by a space
resultado ='veinti '+unidades(c)
^
C:165:tercia: Operator not followed by a space
elif b >=3 and b <= 9:
^^
C:178:tercia: Operator not followed by a space
resultado ='ciento '+unidades(c)
^
C:192:tercia: Operator not followed by a space
resultado ='ciento veinti '+unidades(c)
^
C:204:tercia: Operator not preceded by a space
prefix='quinientos '
^
C:206:tercia: Operator not preceded by a space
prefix='setecientos '
^
C:208:tercia: Operator not preceded by a space
prefix='novecientos '
^
C:210:tercia: Operator not preceded by a space
prefix=unidades(a)+'cientos '
^
R:137:tercia: Too many return statements (23/6)
R:137:tercia: Too many branches (41/12)
R:137:tercia: Too many statements (73/50)
Report
======
141 statements analysed.
Raw metrics
-----------
+----------+-------+------+---------+-----------+
|type |number |% |previous |difference |
+==========+=======+======+=========+===========+
|code |144 |68.25 |NC |NC |
+----------+-------+------+---------+-----------+
|docstring |5 |2.37 |NC |NC |
+----------+-------+------+---------+-----------+
|comment |57 |27.01 |NC |NC |
+----------+-------+------+---------+-----------+
|empty |5 |2.37 |NC |NC |
+----------+-------+------+---------+-----------+
Statistics by type
------------------
+---------+-------+-----------+-----------+------------+---------+
|type |number |old number |difference |%documented |%badname |
+=========+=======+===========+===========+============+=========+
|module |1 |NC |NC |0.00 |0.00 |
+---------+-------+-----------+-----------+------------+---------+
|class |0 |NC |NC |0 |0 |
+---------+-------+-----------+-----------+------------+---------+
|method |0 |NC |NC |0 |0 |
+---------+-------+-----------+-----------+------------+---------+
|function |6 |NC |NC |0.00 |0.00 |
+---------+-------+-----------+-----------+------------+---------+
Duplication
-----------
+-------------------------+------+---------+-----------+
| |now |previous |difference |
+=========================+======+=========+===========+
|nb duplicated lines |0 |NC |NC |
+-------------------------+------+---------+-----------+
|percent duplicated lines |0.000 |NC |NC |
+-------------------------+------+---------+-----------+
Messages by category
--------------------
+-----------+-------+---------+-----------+
|type |number |previous |difference |
+===========+=======+=========+===========+
|convention |32 |NC |NC |
+-----------+-------+---------+-----------+
|refactor |3 |NC |NC |
+-----------+-------+---------+-----------+
|warning |1 |NC |NC |
+-----------+-------+---------+-----------+
|error |0 |NC |NC |
+-----------+-------+---------+-----------+
Messages
--------
+-----------+------------+
|message id |occurrences |
+===========+============+
|C0103 |14 |
+-----------+------------+
|C0322 |6 |
+-----------+------------+
|C0112 |5 |
+-----------+------------+
|C0323 |4 |
+-----------+------------+
|C0111 |2 |
+-----------+------------+
|W0613 |1 |
+-----------+------------+
|R0915 |1 |
+-----------+------------+
|R0912 |1 |
+-----------+------------+
|R0911 |1 |
+-----------+------------+
|C0324 |1 |
+-----------+------------+
Global evaluation
-----------------
Your code has been rated at 7.45/10
I hope it helps.
I highly recommend the use of pylint to rate your code, and keep a standard way of programming, specially in a community of developers. =)
I hope it helps.
